Fluid dispersion unit assembly and method

ABSTRACT

A tray valve assembly for a process column of a type wherein a first, heavier fluid interacts with a second, lighter fluid. A plurality of valves are disposed on a surface of the tray. Each valve of the plurality of valves includes a top surface and at least one securement leg. A first securement leg of is adapted to intercept the first, heavier fluid flow thereby forming a diverting baffle. Each valve includes at least one aperture to facilitate the second, lighter fluid flow therefrom. The at least one aperture is adapted to allow the second, lighter fluid to interact with the first, heavier fluid. Each valve includes a plurality of open side regions. Each valve is adapted to allow the second, lighter fluid to pass outwardly therefrom generally in a direction of the first heavier fluid.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 12/109,781, filed Apr. 25, 2008. U.S. patent application Ser.No. 12/109,781 claims priority from U.S. Provisional Patent ApplicationNo. 60/926,707, filed Apr. 27, 2007. U.S. patent application Ser. No.12/109,781 and U.S. Provisional Patent Application No. 60/926,707 areeach incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to fluid-fluid contacting trays and, moreparticularly, but not by way of limitation, to an improved fluidimpingement device and tray assembly incorporating fluid-deflectorsurfaces with multiple fluid-flow apertures for higher efficiencyoperation, which, in one embodiment, includes gas-liquid contactingtrays incorporating fixed or floating valves with multiple vaporapertures.

2. History of Related Art

Distillation columns are utilized to separate selected components from amulticomponent stream. Generally, such contact columns utilize eithertrays, packing, or combinations thereof. In certain years the trend hasbeen to replace so-called “bubble caps” by sieve and valve trays in mosttray column designs.

Successful fractionation in the column is dependent upon intimatecontact between heavier fluids and lighter fluids. Some contact devices,such as trays, are characterized by relatively high pressure drop andrelatively high fluid hold-up. One type of contact apparatus utilizesfluid in the vapor phase to contact fluid in the liquid phase and hasbecome popular for certain applications. Another type of contactapparatus is high-efficiency packing, which is energy efficient becauseit has low pressure drop and low fluid hold-up. However, these veryproperties at times make columns equipped with structured packingdifficult to operate in a stable, consistent manner. Moreover, manyapplications simply require the use of trays.

Fractionation column trays come in two configurations: cross-flow andcounter flow. The trays generally consist of a solid tray or deck havinga plurality of apertures and are installed on support rings within thecolumn. In cross-flow trays, lighter fluid ascends through the aperturesand contacts heavier fluid moving across the tray, through the “active”area thereof. In this area, the heavier fluid and the lighter fluid mixand fractionation occurs. The heavier fluid is directed onto the tray bymeans of a vertical channel from the tray above. This channel isreferred to as the Inlet Downcomer. The heavier fluid moves across thetray and exits through a similar channel referred to as the ExitDowncomer. The location of the downcomers determines the flow pattern ofthe heavier fluid. If there are two Inlet Downcomers and the heavierfluid is split into two streams over each tray, it is called a two passtray. If there is only one Inlet and one Outlet Downcomer on oppositesides of the tray, it is called a single pass tray. For two or morepasses, the tray is often referred to as a Multipass Tray. The number ofpasses generally increases as the required (design) flow rate increases.It is the active area of the tray, however, which is of criticalconcern.

Addressing now select flow designs, a particularly effective tray inprocess columns is the sieve tray. This tray is constructed with a largenumber of apertures formed in the bottom surface. The apertures permitthe ascending lighter fluid to flow into direct engagement with theheavier fluid that is flowing across the tray from the downcomerdescribed above. When there is sufficient lighter-fluid flow upwardlythrough the tray, the heavier fluid is prevented from running downwardlythrough the apertures (referred to as “weeping”). A small degree ofweeping is normal in trays while a larger degree of weeping isdetrimental to the capacity and efficiency of a tray.

Tray efficiency is also known to be improved in sieve type trays byincreasing the froth height of the heavier fluid and reducing thebackflow of the heavier fluid flowing across the tray. Froth is createdwhen lighter fluid “bubbles” percolate upwardly through the heavierfluid flowing across the tray. The suspension of the lighter fluid inthe heavier fluid prolongs the fluid-fluid contact which enhances theefficiency of the process. The longer the froth is maintained and thehigher the froth is established, the greater the fluid-fluid retention.Higher froth requires smaller “bubbles” formed at a sufficiently slowrate. Likewise, backflow occurs beneath the froth when circulatingcurrents of heavier fluid are established during the heavier fluid flowacross the plate. This generally forms along the lateral portionsthereof. These currents carry the heavier fluid back across the tray ina manner that reduces the concentration-difference driving force formass transfer. It is the concentration-difference between the lighterfluid and the heavier fluid which enhances the effectiveness of thefluid-fluid contact.

The concentration-difference between the lighter fluid and the heavierfluid can be effected in many ways; some reducing efficiency. Forexample, as operating pressure increases, the heavier fluid begins toabsorb lighter fluid as it moves across a tray. This is above thatnormally dissolved in the heavier fluid and represents much largeramounts of lighter-fluid bubbles that are commingled or “entrained” withthe heavier fluid. This lighter fluid is not firmly held and is releasedwithin the downcomer, and, in fact, the majority of said lighter fluidmust be released otherwise the downcomer cannot accommodate the heavierfluid/lighter fluid mixture and will flood, thus preventing successfultower operation. This phenomena is generally deemed to occur whenoperating pressure is such as to produce a lighter fluid density aboveabout 1.0 lbs/cu. ft. and typically amounts to about 10 to 20% of thelighter fluid by volume. For conventional trays, as shown below, thereleased lighter fluid must oppose the descending frothy lighterfluid/heavier fluid mixture flowing over the weir into the downcomer. Inmany cases, such opposition leads to poor tower operation and prematureflooding.

When a vapor comprises the lighter fluid and a liquid comprises theheavier fluid, there are specific performance issues. Certainperformance and design issues are seen in the publication “DistillationTray Fundamentals”, M. J. Lockett, Cambridge University Press, 1986.Other examples are seen in several prior art patents, which include U.S.Pat. Nos. 3,959,419, 4,604,247 and 4,597,916, each assigned Glitsch,Inc., and U.S. Pat. No. 4,603,022 issued to Mitsubishi Jukogyo KabushikiKaisha of Tokyo, Japan. A particularly relevant reference is seen inU.S. Pat. No. 4,499,035 assigned to Union Carbide Corporation thatteaches a gas-liquid contacting tray with improved inlet bubbling means.A cross-flow tray of the type described above is therein shown withimproved means for initiating bubble activity at the tray inletcomprising spaced apart, imperforate wall members extendingsubstantially vertically upwardly and transverse to the liquid flowpath. The structural configuration is said to promote activity over alarger tray surface than that afforded by simple perforated trayassemblies. This is accomplished in part by providing a raised regionadjacent the downcomer area for facilitating gas ascension therethrough.

U.S. Pat. No. 4,550,000 assigned to Shell Oil Company teaches anapparatus for contacting a liquid with a gas in a relationship betweenvertically stacked trays in a tower. The apertures in a given tray areprovided for the passage of gas in a manner less hampered by liquidcoming from a discharge means of the next upper tray. This is providedby perforated housings secured to the tray deck beneath the downcomersfor breaking up the descending liquid flow. Such advances in traydesigns improve efficiency within the confines of prior art structures.Likewise, U.S. Pat. No. 4,543,219 assigned to Nippon Kayaku KabushikiKaisha of Tokyo, Japan teaches a baffle-tray tower. The operationalparameters of high gas-liquid contact efficiency and the need for lowpressure loss are set forth. Such references are useful in illustratingthe need for high efficiency lighter fluid/heavier fluid contact in trayprocess towers. U.S. Pat. No. 4,504,426 issued to Karl T. Chuang et. al.and assigned to Atomic Energy of Canada Limited is yet another exampleof gas-liquid contacting apparatus.

Several prior patents have specifically addressed the tray design andthe apertures in the active tray deck area itself. For example, U.S.Pat. No. 3,146,280 is a 1964 patent teaching a directional float valve.The gas is induced to discharge from the inclined valve in a predefineddirection depending on the orientation of the valve in the tray deck.Such valve configurations are often designed for particular applicationsand flow characteristics. Tray valves with weighted sides and variousshapes have thus found widespread acceptance in the prior art. Acircular valve structure is shown in U.S. Pat. No. 3,287,004 while arectangular valve structure is shown in U.S. Pat. No. 2,951,691. Both ofthese patents issuing to I. E. Nutter, teach specific aspects ofgas-liquid contact flow utilizing tray valve systems. Such specializeddesigns are necessary because lighter fluid/heavier fluid flow problemsmust be considered for each application in which a tray is fed by adowncomer. The type of flow valve, its orientation, and thelighter-fluid flow apertures for lighter fluid-heavier fluid flowinteraction are some of the issues addressed by the present invention.

Addressing specifically now the type of flow valve, its orientation, andthe lighter-fluid flow apertures that currently are taught by the priorart. Attention is directed to two patents in which one of theco-inventors of the present application, Michael J. Binkley, is aco-inventor. U.S. Pat. Nos. 5,147,584 and 5,120,474, both teach certainvalve-tray designs and contact tray assemblies and methods. In thecontact tray assemblies and the valve designs, it may be seen that theindividual valves whether fixed or floating, are illustrated in thedrawings with solid surfaces. In other words, both the front and rearlegs, as well as the top surface of the valves, whether floating orfixed, are shown to be of solid construction. Other contact-tray valveassemblies are set forth and shown in U.S. Pat. Nos. 6,145,816;5,911,922; 5,762,834; and 6,089,550. Each of these patents furtherillustrate aspects of contact tray assemblies and methods as well asvalve designs. Additional patents which should likewise be reviewedrelative to contact trays include the following four patents in whichthe Applicant hereof, Michael J. Binkley, is a co-inventor and include:U.S. Pat. Nos. 5,453,222; 4,956,127; 5,106,556; 5,277,848; and5,192,466. The above-referenced patents and statements with regard tothe related art are set forth for purposes of understanding theintricacies of the design considerations in contact-tray assembly andmethod configurations. It would be an advantage to provide a method ofand apparatus for enhanced fluid flow manifesting increased efficiencywith a valve design having either a fixed or floating configurationrelative to the tray and with multiple fluid-flow apertures formedtherein for enhanced fluid interaction. The methods of and apparatus forvalve tray assemblies and methods are herein set forth and shown.

SUMMARY OF THE INVENTION

A tray valve assembly for a process column of a type wherein a first,heavier fluid flows downwardly from a downcomer onto a tray andthereacross in a first direction through which a second, lighter fluidflows upwardly therethrough for interaction and mass transfer with theheavier fluid before passing therefrom. The assembly comprises aplurality of apertures formed on a surface of the tray for facilitatingthe lighter fluid flow upwardly therethrough, a plurality of valvesdisposed across the surface of the tray and mounted above the pluralityof apertures formed on the surface of the tray, each valve of theplurality of valves comprising a top surface and at least one securementleg, and a first securement leg of the at least one securement leg isadapted to intercept the heavier fluid flow in the first directionforming a diverting baffle for engaging the heavier fluid flow acrossthe tray. Each valve of the plurality of valves comprising at least oneaperture to facilitate the lighter fluid flow therefrom and furthercomprising a first aperture in the first securement leg wherein thefirst aperture is adapted to allow the lighter fluid to flow in a seconddirection to interact with the heavier fluid flow in the first directionfor lighter fluid aeration thereof. Each valve of the plurality valvescomprising a plurality of open side regions for allowing ascendinglighter fluid flow to pass outwardly therefrom in generally oppositelydispersed directions for contact with the heavier fluid flow in thefirst direction and each valve of the plurality of valves is adapted toallow the ascending lighter fluid flow to pass outwardly therefromgenerally in the first direction of the heavier fluid flow passing overthe top surface for facilitating a propulsion of the heavier fluid flowtherefrom and across the tray.

A method of mixing a first, heavier fluid flowing downwardly from adowncomer onto a tray and thereacross in a first direction with asecond, lighter fluid flowing upwardly therethrough for interaction andmass transfer with the heavier fluid before passing therefrom. Themethod includes forming, on a surface of the tray, a plurality ofapertures for facilitating the lighter fluid flow upwardly therethrough,disposing, above the plurality of apertures formed on the surface of thetray, a plurality of valves, wherein each valve of the plurality ofvalves comprising a top surface and at least one securement leg, andintercepting, via a first securement leg of the at least one securementleg, the heavier fluid flow in the first direction to form a divertingbaffle for engaging the heavier fluid flow across the tray. The methodfurther includes forming, in each valve of the plurality of valves, aplurality of apertures to facilitate the lighter fluid flow therefrom,wherein a first aperture is formed in the first securement leg,allowing, via the first aperture, the lighter fluid to flow in a seconddirection to interact with the heavier liquid flow in the firstdirection for lighter fluid aeration thereof, allowing, via a pluralityof open side regions, the ascending lighter fluid flow to pass outwardlytherefrom in generally oppositely disposed directions for contact withthe heavier fluid flow in the first direction, and allowing, via eachvalve of the plurality of valves, ascending lighter fluid flow to passoutwardly therefrom generally in the first direction of heavier fluidflow passing over the top surface for facilitating a propulsion of theheavier fluid flow therefrom and across the tray.

A valve for use in a tray valve assembly for a process column of a typewherein a first, heavier fluid flows downwardly from a downcomer onto atray and thereacross in a first direction through which a second,lighter fluid flows upwardly therethrough for interaction and masstransfer with the heavier fluid before passing therefrom. The valveincludes at least one securement leg having a first aperture formedtherein, a top surface having a second aperture formed therein, aplurality of open side valve regions, and a first securement leg of theat least one securement leg being adapted to intercept the heavier fluidflow in the first direction forming a diverting baffle for engaging theheavier fluid flow across the tray. The first aperture being adapted toallow the lighter fluid to flow in a second direction to interact withthe heavier fluid flow in the first direction for lighter fluid aerationthereof. The plurality of open side valve regions being adapted to allowascending lighter fluid flow to pass outwardly therefrom in generallyoppositely disposed directions for contact with the heavier fluid flowin the first direction. The valve is further adapted to allow theascending lighter fluid flow to pass outwardly therefrom generally inthe first direction of the heavier fluid flow passing over the topsurface for facilitating a propulsion of the heavier fluid flowtherefrom and across the tray.

A valve for use in a tray valve assembly for a process column of a typewherein a first, heavier fluid flows downwardly from a downcomer onto atray and thereacross in a first direction through which a second,lighter fluid flows upwardly therethrough for interaction and masstransfer with the heavier fluid before passing therefrom. The valveincludes a first securement leg having at least a first aperture formedtherein, a second securement leg having at least a second apertureformed therein, a plurality of open side valve regions, the firstsecurement leg being adapted to intercept the heavier fluid flow in thefirst direction forming a diverting baffle for engaging the heavierfluid flow across the tray. The first aperture being adapted to allowthe lighter fluid to flow in a second direction to interact with theheavier fluid flow in the first direction for lighter fluid aerationthereof. The plurality of open side valve regions being adapted to allowthe ascending lighter fluid flow to pass outwardly therefrom ingenerally oppositely disposed directions for contact with the heavierfluid flow in the first direction. The valve is further adapted to allowthe ascending lighter fluid flow to pass outwardly therefrom generallyin the first direction of the heavier fluid flow for facilitating apropulsion of the heavier fluid flow therefrom and across the tray.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the method and system of the presentinvention may be obtained by reference to the following DetailedDescription when taken in conjunction with the accompanying Drawingswherein:

FIG. 1 is a perspective view of a prior art packed column with varioussections cut away for illustrating, diagrammatically, a variety oftower;

FIG. 2 is a diagrammatic, side-elevational, cross-sectional view of aprior art downcomer-tray assembly secured within a process tower andillustrating the flow of heavier fluid thereacross and lighter fluidupwardly therethrough;

FIG. 3 is a top-plan, diagrammatic view of a prior art tray illustratingproblems with fluid flow thereacross;

FIG. 4 is a perspective view of one embodiment of a downcomer-trayassembly constructed in accordance with the principles of the presentinvention and having portions thereof cut away for purposes of clarity;

FIG. 5 is an enlarged perspective view of one valve of the tray surfacein accordance with an embodiment of the present invention;

FIG. 6 is a side-elevational cross-sectional view of the valve structureof FIG. 5 in accordance with an embodiment of the present invention;

FIG. 7 is a side-elevational view of an alternative embodiment of thevalve structure of FIG. 5 in accordance with an embodiment of thepresent invention;

FIG. 8 is a perspective view of a valve structure comprising a fixedrectangular valve assembly in accordance with an embodiment of thepresent invention;

FIG. 9 is a perspective view of a valve structure comprising a fixedtrapezoidal valve assembly in accordance with an embodiment of thepresent invention; and

FIG. 10 is a perspective view of a valve assembly comprising a fixedtrapezoidal valve assembly in accordance with an embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Various embodiments of the present invention will now be described morefully with reference to the accompanying drawings. The invention may,however, be embodied in many different forms and should not beconstructed as limited to the embodiments set forth herein; rather, theembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope of the invention to thoseskilled in the art.

Referring first to FIG. 1, there is shown a fragmentary, perspectiveview of an illustrative prior art packed exchange tower or column 12with various sections cut away for showing a variety of tower internalsand the utilization of one embodiment of an improved high-capacity trayassembly. The exchange column 10 of FIG. 1 comprises a cylindrical tower12 having a plurality of packing bed layers 14 and trays disposedtherein. A plurality of manways 16 are likewise constructed forfacilitating access to the internal region of the tower 12. Alsoprovided are side stream draw-off line 20, heavier-fluid side feed line18, and side stream lighter-fluid feed line or reboiler return line 32.A reflux return line 34 is provided atop the column 10.

In operation, heavier fluid 13 is fed into the column 10 through refluxreturn line 34 and side stream feed-input feed line 18. The heavierfluid 13 flows downwardly through the tower 12 and ultimately leaves thetower 12 either at side stream draw-off line 20, or at bottom-streamdraw-off line 30. In the case of a vapor-liquid tower, the heavier fluid13, during its downward flow, is depleted of some material whichevaporate from it as it passes through the trays and packing beds, andis enriched or added to by material which condenses into it out of thelighter fluid stream.

Still referring to FIG. 1, the exchange column 10 is diagrammaticallycut in half for purposes of clarity. In this illustration, the column 10includes a lighter-fluid outlet in overhead line 26 disposed atop thetower 12 and a lower skirt 28 disposed in the lower region of the tower12 around bottom stream takeoff line 30 coupled to a reboiler (notexplicitly shown). Reboiler return conduit 32 is shown disposed abovethe lower skirt 28 for recycling lighter fluid therein upwardly throughthe trays and/or packing layers 14. Reflux from condensers is providedin the upper tower region 23 through entry conduit 34 wherein reflux isdistributed throughout a distributor 36 across upper packing bed 38.According to exemplary embodiments, the upper packing bed 38 is of thestructured packing variety. The regions of the exchange column 10beneath the upper packing bed 38 are shown for the purpose ofillustration and include a heavier fluid collector 40 disposed beneath asupport grid 41 in support of the upper structured packing 38. Thecolumn 10 is presented with cut-line 43 for illustrating the fact thatthe tower internals arrangement is diagrammatical only and is providedfor referencing various component arrays therein.

Referring still to FIG. 1, an assembly of a pair of trays is also shownfor purposes of illustration. In many instances, process columns containonly packing, only trays, or combinations of packing and trays. Thepresent illustration is, however, a combination for purposes ofdiscussion of the overall tower and its operation. A trayed columnusually contains a plurality of trays 48 of the type shown herein. Inmany instances, the trays 48 are valve or sieve trays. According to anexemplary embodiment, the trays 48 are valve trays. The trays 48comprise plates which may be, for example, punched or slotted inconstruction. Within the scope of the invention and for the purposes ofthe description of various embodiments herein, the configurationreferred to as a “valve” includes anything at the intersection of andfacilitating the contact between a lighter fluid and a heavier fluid.The lighter fluid and the heavier fluid engage at or along the tray 48and, in some assemblies, are permitted to flow through the same openingsin a counter-current flow arrangement. Optimally, the lighter-fluid andheavier-fluid flows reach a level of stability. With the utilization ofappropriate downcomers, to be described in more detail below, thisstability may be achieved with a relatively low flow rate permitting theascending lighter fluid to mix with the descending heavier fluid. Insome embodiments, no downcomers are used and the lighter fluid and theheavier fluid use the same openings, alternating as the respectivepressures change.

According to an exemplary embodiment, cross-flow valve trays 48 and 49and downcomers 53 and 69 are illustrated. Tray 48 is constructed with aplurality of floating valves. Tray 49 also illustrates a raised inletsection 51 beneath downcomer 53, which is substantially planar, formedwith a plurality of apertures, and which may include a series ofmomentum deflector barriers, as will be described below. The raisedinlet area is described in more detail in U.S. Pat. No. 4,956,127 (the'127 patent). Corrosion is another consideration in designing packedtowers and for the selection of the material, design, and thefabrication of the tower internals.

Referring now to FIG. 2, there is shown a is a diagrammatic,side-elevational, cross-sectional view of a prior art downcomer-trayassembly secured within a process tower and illustrating the flow ofheavier fluid thereacross and lighter fluid upwardly therethrough. Anupper tray 48 comprises a first valved panel. The lower tray 49 is alsoof generally planar construction across its central active area 52,having a plurality of valves 100 mounted thereon, disposed therein, orformed therefrom as diagrammatically shown. Heavier fluid 13 travelsdown a downcomer 53 having a tapered or mitered bottom section 54, fromtray 48 disposed thereabove. The tapered section 54 of the downcomerprovides a clearance angle for lighter fluid flow from the active inletarea, which clearance angle affords a horizontal flow vector to thelighter fluid vented through raised panel 51. The heavier fluid 13engages lighter fluid 15 discharged from the raised active panel area 51beneath the downcomer 53.

Still referring to FIG. 2, the froth 61 extends with a relativelyuniform height, shown in phantom by line 63 across the width of the tray49 to the opposite end 65 where a weir 67 is established for maintainingthe froth height 63. The accumulated froth at this point flows over thetop of the weir 67 into associated downcomer 69 that carries the frothdownwardly into a mitered region 70 where the heavier fluid accumulatesand disperses upon active inlet region 71 therebeneath. Again activeinlet region 71 is shown herein diagrammatically for purposes ofillustration only. As stated herein, the area of holes and perforationsfor a single cross-flow plate establish the active length of the plateand the zone in which the froth 61 is established. It should be notedthat the present invention would also be applicable to multipledowncomer configurations, wherein the downcomers and raised, activeinlet areas (if incorporated) may be positioned in intermediate areas ofthe trays as also described below. By increasing the total active areaof active inlet areas 51 and 71, greater capacity and efficiency isachieved. It is also the manner of flow of the heavier fluid 13 acrossthe tray 49 which is critical to tray efficiency.

Referring now to FIG. 3, there is shown a top-plan, diagrammatic view ofa prior art tray illustrating problems with fluid flow thereacrossthere.The prior art tray 72 is illustrated herein as a round unit having afirst conventional downcomer for feeding heavier fluid upon a solid,underlying panel 73 and then to the tray 74. A second downcomer 74Acarries heavier fluid away from the tray. A plurality of arrows 75illustrate the non-uniform flow of heavier fluid 13 typically observedacross a conventional prior art tray which does not address thecirculation issue. Circular flow is shown to be formed on both sides ofthe plate lateral to the direction of primary flow. The formation ofthese retrograde flow areas, or recirculation cells 76, decreases theefficiency of the tray. Recirculation cells 76 are the result ofretrograde flow near the walls of the process column and this backflowproblem becomes more pronounced as the diameter of the column increases.With the increase in retrograde flow and the resultant stagnation effectfrom the recirculation cells, concentration-difference driving force formass transfer between the counter-flowing streams is reduced. Thereduction in concentration-difference driving force will result in morecontact or height requirement for a given separation in the column.Although back mixing is but a single aspect of plate efficiency, thereduction thereof is provided concurrently with the other advantageshereof. Reference is again made to the plate efficiency discussion setforth in above referenced '127 patent.

Referring now to FIG. 4, there is shown a perspective view of adowncomer-tray assembly 99 constructed in accordance with principles ofthe present invention and having portions thereof cut away for purposesof clarity and illustrated with a downcomer and raised inlet region.Conventional materials such as, for example, stainless steel or othercorrosion resistant material may be utilized, as is well known in theart. The tray 49, as shown herein, is also constructed for placement inthe tower 12 by conventional means. In the tower, a feeding downcomer102, having an inclined face 103, is disposed over a raised inlet region104 for discharging heavier fluid 13 to tray 49. A weir 82 is disposedon the opposite side of tray 49 whereby a second downcomer is disposedfor carrying heavier fluid 13 away from the tray 49. Heavier fluid 13spills down upon the inlet region 104 and over upstanding edge 112 ontothe tray 49. It should be noted that neither the downcomer nor theraised inlet region 104 is a part of the present invention.

Still referring to FIG. 4, there is shown a plurality of valves 100uniformly spread across tray 49. The plurality of valves 100 arediagrammatically shown, but, as will be more fully described below, theplurality of valves 100 can be formed in both “fixed” and “floating”configurations. In one embodiment, the plurality of valves 100 areuniformly disposed across the entire surface of tray 49. However,various other embodiments are contemplated where the pattern of theplurality of valves 100 is staggered or varied across a single tray 49.As will be described in more detail below, the heavier fluid 13, flowingacross the tray 49, encounters a lighter fluid 15 flowing up through theplurality of valves 100 for interaction therewith. The design of theplurality of valves 100 is configured to increase the efficiency of thatinteraction.

In one embodiment, the plurality of valves 100 are diagrammaticallyshown as rectangles, but, as will be more fully described below, theplurality of valves 100 can be formed of a plurality of shapes. In oneembodiment, the valves 100 are uniformly disposed across the entiresurface of tray 49. For example, FIG. 4 shows a portion of two differentexemplary uniform patterns 1100.

Referring now to FIG. 5, there is shown an enlarged perspective view ofa floating valve 100 in accordance with an embodiment of the presentinvention. The floating valve 100 is a separate structure inserted intotray 49. The floating valve 100 comprises a front securement leg 132 anda rear securement leg 134 depending from a generally circular topsurface 130. According to an exemplary embodiment, the top surface 130comprises a circular disc. The floating valve 100 is mounted within thesurface of tray 49 and disposed above an aperture 136 formed therein.The aperture 136 includes a pair of slotted regions 138 and 139 adaptedfor receiving the securement legs 132 and 134, respectively. There aremultiple advantages in utilizing this type of floating valve 100. Theorientation of the floating valve 100 relative to the heavier fluid flowis determined by the alignment and spacing of the slotted regions 138and 139 which allows for not only the upward flotation of the circulardisc 130 for the passage of lighter fluid therebeneath, but also thesecured orientation thereof. It is important that the valves 100maintain the orientation shown in FIG. 4. According to exemplaryembodiments, the floating valve 100 acts as a deflecting plate thatdeflects impinging fluid-flow across the tray 49 in order to disperserising fluid 15 coming through the tray 49 into heavier fluid 140 streamthereacross.

The floating valve 100 includes one or more apertures on each surfacethereof. In one embodiment, the valve 100 has one aperture on threesurfaces forming three distinct apertures therein. Aperture 137C isformed in the top surface 130 thereof while upstream aperture 137D isformed in the front securement leg 132 thereof and downstream aperture137E is formed in the rear securement leg 134 thereof. These apertures137C, 137D, 137E in conjunction with the open valve areas 137A and 137B,permit an improved lighter fluid/heavier fluid interaction due to themultiplicity of lighter-fluid flow areas constructed with the valve 100.According to an exemplary embodiment, the size of the valve 100 has beenshown to be effective in the assembly of a tray having an active areawith approximately 25-50 valves per square foot. Other sizes are, ofcourse, contemplated by the present invention. This valve density persquare foot is substantially higher than possible with valves of theconventional size of 11/2″ to 17/8″ in diameter. Prior art valve densityon the order of 12-14 valves per square foot has been common. Theincreased density is a result of the smaller size of valve 100 and itsdirectional thrust design as herein described, which permits it to bespaced close to adjacent valves as shown. The various embodiments of thepresent invention are a marked advance over prior art designs utilizinglarger valves and broader spacing. The efficiency of the tray is thoughtto be enhanced therefrom.

Still referring to FIG. 5, heavier-fluid flow is illustrated with arrow140 flowing in a direction of the circular disc 130. As theheavier-fluid flow 140 engages the frontal leg 132 of the floating valve100, it is seen to split into bi-directional flow 141 traveling aroundthe circumference of the circular aperture 136. Lighter fluid 15 ventingbeneath circular disc 130 is represented by arrows 142A, 142B, 142C,142D, and 142E, which arrows illustrate the biased direction that thelighter fluid 15 has in discharge from beneath the circular disc 130.More particularly, it is shown in FIG. 5 how the heavier-fluid flow 140interacts with the lighter-fluid flow 15 due to the multiplicity ofapertures formed in the valve 100. As shown herein and as describedabove, the floating valve 100 is constructed with the multiplicity ofareas for lighter-fluid flow, including open side regions 137A and 137B,top aperture 137C, upstream aperture 137D, and downstream aperture 137E.It may be seen that the lighter fluid flow 142A, 142B, 142C, 142D and142E each extend through their respective valve openings 137A and 137Bas well as apertures 137C, 137D and 137E. These lighter-fluid flow areasallow interaction between the lighter fluid 15 and the heavier fluid 140in such a way that maximum interaction is afforded.

Referring still to FIG. 5, it may be seen that the orientation of thefloating valve 100 both induces the lighter fluid flow 142C to be in adirection substantially along the path of the heavier fluid flow 140 tofurther promote the directional flow of heavier fluid as well as thelighter fluid flow 142E occurring against the path of the heavier fluidflow 140 to further enhance interaction. It should be noted that the“directional thrust” aspect of the valve is provided in conjunction withthe multiple-aperture interaction therein afforded by the multipleapertures across the legs and top surface thereof to further enhance theheavier fluid/lighter fluid interaction.

Referring now to FIG. 6 there is shown, according to an exemplaryembodiment, the floating valve 100 including top surface 130 containingaperture 137C of FIG. 5 in a side elevational, cross-section view. Frontsecurement leg 132 is seen to include upstream aperture 137D foraffording lighter fluid/heavier fluid interaction with heavier-fluidflow 140 coming across the tray 49. Lighter fluid 15 ascending throughthe tray 49 is exhausted as represented by arrows 142A, 142B, 142C, 142Dand 142E. The escaping lighter fluid flow represented by arrows 142A,142B, 142C, 142D, and 142E interacts immediately with heavier fluid flow140 and continues downstream of the rear securement leg 134 havingdownstream aperture 137E formed therein. In one embodiment, the apertureon the top surface or leg surface is punched to leave a tab that alsofunctions as a deflection surface.

Referring now to FIG. 7 there is shown a side-elevational view of analternative embodiment of a valve structure in accordance with anembodiment of the present invention. Tray 49 includes a valve 200 whichis constructed with a downstream aperture 201, a top aperture 202, andan upstream aperture 203 which further facilitate lighter-fluiddispersion therefrom in conjunction with the dispersion of lighter fluidthrough the openings at the sides of the valve as described above. Inthis particular embodiment, a floating valve 200 is seen with anangulated top surface 220 relative the flow of flow 140 of heavier fluidthereacross. In this embodiment the angulated top surface 220 of thefloating valve 200 faces the incoming flow 140 to enhance thefluid-fluid interaction and reduce resistance to heavy fluid flow,however, the angulated top surface 220 may be angulated in the oppositedirection or any other direction depending on the design requirements.It should further be noted that valves of both floating and fixedconfiguration are contemplated by the spirit and scope of the presentinvention.

Referring now to FIG. 8, there is illustrated a perspective view of avalve structure 200 comprising a fixed rectangular valve assembly inaccordance with an embodiment of the present invention. The fixed valve200 comprises a front securement leg 204 and a rear securement leg 205depending from a generally rectangular top surface 201. The fixed valve200 is mounted within the surface of tray 49 and disposed above anaperture 212 formed therein. The fixed valve 200 includes one or moreapertures on each surface thereof. In one embodiment, the fixed valve200 includes one aperture on three surfaces forming three distinctapertures therein. Aperture 202 is formed in the top surface 201 thereofwhile aperture 208 is formed in the front securement leg 204 thereof andaperture 203 is formed in the rear securement leg 205 thereof. In theseembodiments, the front and rear securement legs 204, 205 extend from thetop surface 201 of the fixed valve 200 down to tray 49 and are securedthereagainst. According to an exemplary embodiment, aperture 202 isshown as a slot whose length runs transverse to the length of the topsurface 201 of the floating valve 200. However, it is contemplated thatthe aperture 202 can be of any size and shape and in any directiondepending on the design requirements. According to an exemplaryembodiment, only fixed rectangular valves 200 are illustrated; however,the valves 200 can be formed in both “fixed” and “floating”configurations.

Similarly, FIG. 9, there is illustrated a perspective view of a valvestructure 200 comprising a fixed trapezoidal valve assembly inaccordance with an embodiment of the present invention. The fixed valve200 comprises a front securement leg 204 and a rear securement leg 205depending from a generally trapezoidal top surface 201. The fixed valve200 is mounted within the surface of tray 49 and disposed above anaperture formed therein. The fixed trapezoidal valve 200 includes one ormore apertures on each surface thereof. In one embodiment, the fixedvalve 200 has one aperture on three surfaces forming three distinctapertures therein. Aperture 202 is formed in the top surface 201 thereofwhile aperture 208 is formed in the front securement leg 204 thereof andaperture 203 is formed in the rear securement leg 205 thereof. Apertures202, 203, 208 operate to allow the discharge of lighter fluid therefrom.In these embodiments, the front and rear securement legs 204, 205 extendfrom the top surface 201 of the fixed valve 200 down to tray 49 and aresecured thereagainst. According to an exemplary embodiment, the aperture202 is shown as a slot whose length runs transverse to the length of thetop surface 201 of the valve 200. However, it is contemplated that theaperture 202 can be of any size and shape and in any direction dependingon the design requirements. According to an exemplary embodiment, onlyfixed trapezoidal valves 200 are illustrated; however, the valves 200can be formed in both “fixed” and “floating” configurations.

Referring now to FIG. 10, there is illustrated a perspective view of avalve assembly 300 comprising a fixed trapezoidal valve assembly inaccordance with an embodiment of the present invention. The fixedtrapezoidal valve 300 is shown made from a protrusion of tray 49. Inthis embodiment, the fixed trapezoidal valve 300 acts as a deflectingplate that deflects impinging fluid-flow across the tray 49 in order todisperse rising lighter fluid coming through the tray 49 into theheavier fluid stream thereacross. According to an exemplary embodiment,the fixed trapezoidal valve 300 can be an integral unit formed out ofthe tray 49 or can be a separate structure fastened to the tray 49 atone end. In one embodiment, the fixed trapezoidal valve 300 is formed bypunching a hole into the tray 49 of less than 360 degrees so that a tab349 is formed. The tab 349 includes a top aperture 302A and frontaperture 302B. According to an exemplary embodiment, the aperture 302Ais shown as a slot whose length runs transverse to the length of the topsurface of the tab 349 while aperture 302B is “T” shaped. However, it iscontemplated that the apertures 302A and 302 B can be of any size andshape and in any direction depending on the design requirements.

In summary, this patent application is provided to further teach theutilization of both fixed and floating valves in a contact tray assemblythat is designed to enhance lighter fluid/heavier fluid interactionutilizing a multiplicity of valve configurations. The contact trays mayhave a plurality of valves of a multitude of shapes. The plurality ofvalves may have one or more apertures in the top and one or moreapertures on one or more legs depending from the top surface.

Although various embodiments of the method and apparatus of the presentinvention have been illustrated in the accompanying Drawings anddescribed in the foregoing Detailed Description, it will be understoodthat the invention is not limited to the embodiments disclosed, but iscapable of numerous rearrangements, modifications and substitutionswithout departing from the spirit of the invention as set forth herein.

What is claimed is:
 1. A tray valve assembly for a process column of atype wherein a first fluid flows downwardly from a downcomer onto a trayand thereacross in a first direction through which a second fluid flowsupwardly therethrough for interaction and mass transfer with the heavierfluid before passing therefrom, the assembly comprising: a plurality ofapertures formed on a surface of the tray for facilitating flow of thesecond fluid flow upwardly therethrough; a plurality of floating valvesdisposed across the surface of the tray and mounted above the pluralityof apertures, each floating valve of the plurality of floating valvescomprising a top surface and at least one securement leg operativelycoupled to the top surface; a first securement leg of the at least onesecurement leg, the first securement leg being adapted to intercept flowof the first fluid in the first direction by forming a diverting bafflefor engaging the first fluid; a first aperture disposed in the firstsecurement leg of each floating valve of the plurality of floatingvalves, the first aperture being operable to allow the second fluid toflow in a second direction to interact with flow of the first fluid inthe first direction; a plurality of open side regions disposed in eachfloating valve of the plurality of floating valves for allowing flow ofthe second fluid to pass outwardly therefrom in generally oppositelydispersed directions for contact with flow of the first fluid in thefirst direction; and wherein each floating valve of the plurality offloating valves allows the flow of the second fluid to pass outwardlytherefrom generally in the first direction thereby facilitating apropulsion of the first fluid across the tray.
 2. The tray valveassembly of claim 1, wherein each floating valve of the plurality offloating valves is rectangular in shape.
 3. The tray valve assembly ofclaim 1, wherein each floating valve of the plurality of floating valvesis trapezoidal in shape.
 4. The tray valve assembly of claim 1, whereineach floating valve of the plurality of floating valves is circular inshape.
 5. The tray valve assembly of claim 1, wherein each floatingvalve of the plurality of floating valves comprises a pair of oppositelydisposed securement legs.
 6. The tray valve assembly of claim 5, whereineach aperture of the plurality of apertures formed on the surface of thefirst tray comprises a pair of slotted regions that receive the pair ofoppositely disposed securement legs.
 7. The tray valve assembly of claim1, wherein the at least one aperture and the plurality of open sideregions permit interaction between flow of the first fluid flow and flowof the second fluid to achieve maximum interaction.
 8. The tray valveassembly of claim 1, wherein the top surface of each floating valve ofthe plurality of floating valves comprises a circular disc.
 9. The trayvalve assembly of claim 1, wherein the top surface of each floatingvalve of the plurality of floating valves is non-angulated relative toflow of the first fluid in the first direction.
 10. The tray valveassembly of claim 1, wherein the top surface of each floating valve ofthe plurality of floating valves is angulated relative to the flow ofthe first fluid in the first direction.
 11. The tray valve assembly ofclaim 1, wherein the top surface of each floating valve of the pluralityof floating valves comprises at least a second aperture.
 12. The trayvalve assembly of claim 11, wherein the second aperture allows thesecond fluid to ascend therethrough for contact with flow of the firstfluid in the first direction.
 13. The tray valve assembly of claim 1,further comprising a second securement leg of the at least onesecurement leg having at least a third aperture therein.
 14. The trayvalve assembly of claim 1, wherein the second fluid comprises a vapor.15. A method of mixing a first fluid flowing downwardly from a downcomeronto a tray and thereacross in a first direction with a second fluidflowing upwardly therethrough for interaction and mass transfer with thefirst fluid before passing therefrom, the method comprising: forming, ona surface of the tray, a plurality of apertures for facilitating flow ofthe second fluid upwardly therethrough; disposing, above the pluralityof apertures formed on the surface of the tray, a plurality of floatingvalves, wherein each floating valve of the plurality of floating valvescomprising a top surface and at least one securement leg operativelycoupled to the top surface; intercepting, via a first securement leg ofthe at least one securement leg, flow of the first fluid in the firstdirection to form a diverting baffle for engaging flow of the firstfluid across the tray; forming, in each floating valve of the pluralityof floating valves, a plurality of apertures to facilitate flow of thesecond fluid therefrom, wherein at least a first aperture is formed inthe first securement leg; allowing, via the first aperture, the secondfluid to flow in a second direction to interact with the heavier liquidflow in the first direction for lighter fluid aeration thereof;allowing, via a plurality of open side regions, flow of the second fluidto pass outwardly therefrom in generally oppositely disposed directionsfor contact with flow of the first fluid in the first direction; andallowing, via each floating valve of the plurality of floating valves,flow of the second fluid to pass outwardly therefrom generally in thefirst direction thereby facilitating a propulsion of flow of the firstfluid across the tray.
 16. The method of claim 15, wherein the topsurface of each floating valve of the plurality of floating valves isnon-angulated relative to flow of the first fluid in the firstdirection.
 17. The method of claim 15, wherein the top surface of eachfloating valve of the plurality of floating valves is angulated relativeto flow of the first fluid in the first direction.
 18. The method ofclaim 15, wherein the top surface of each floating valve of theplurality of floating valves comprises at least a second aperture. 19.The method of claim 18, wherein the second aperture allows the secondfluid to ascend therethrough for contact with flow of the first fluid inthe first direction.
 20. A floating valve for use in a tray valveassembly for a process column of a type wherein a first fluid flowsdownwardly from a downcomer onto a tray and thereacross in a firstdirection through which a second fluid flows upwardly therethrough forinteraction and mass transfer with the first fluid before passingtherefrom, the floating valve comprising: a top surface; a firstsecurement leg coupled to the top surface, the first securement legcomprising at least a first aperture formed therein; a second securementleg coupled to the top surface, the second securement leg comprising atleast a second aperture formed therein; a plurality of open side valveregions; the first securement leg being operable to intercept flow ofthe first fluid in the first direction by forming a diverting baffle forengaging flow of the first fluid across the tray; the first aperturebeing operable to allow the second fluid to flow in a second directionto interact with flow of the first fluid in the first direction; theplurality of open side valve regions allowing flow of the second fluidflow to pass outwardly therefrom in generally oppositely disposeddirections for contact with flow of the first fluid in the firstdirection; and the floating valve allowing the second fluid to passoutwardly therefrom generally in the first direction of flow of thefirst fluid for facilitating a propulsion of the first fluid therefromand across the tray.
 21. The floating valve of claim 20, furthercomprising a top surface having at least a third aperture formedtherein.
 22. The floating valve of claim 21, wherein the third apertureallows the second fluid to ascend therethrough for contact with thefirst fluid.